【作者】 徐正华；

【导师】 张远深；

【作者基本信息】 兰州理工大学 ， 机械电子工程， 2007， 硕士

【摘要】 气动技术具有一系列显著优点,在工业生产中得到了越来越广泛的应用,已成为实现自动化技术不可缺少的手段。进入上世纪90年代后,气动技术更是突破传统死区,经历着飞速发展。气动伺服技术作为本学科的前沿研究领域,备受人们的重视。气动伺服定位技术已能使气缸在高速运动下实现任意点、高精度定位,突破了传统的气动定位方法。基于众多中小企业关于工程可行性好、性价比高的气动自动化设备改造的需求,本文提出了一种低成本的基于比例压力阀的直线气缸位置控制系统,仿真结果表明其具有理想的控制性能,因而以期能在工程中获得推广和应用。在工业自动化领域,存在大量的旋转位置伺服控制需求,因此,对气动旋转位置伺服控制进行研究有实用价值。摆动气缸是一种常用的气动旋转驱动装置,由于摆动气缸较小的行程和较大的摩擦力矩使得对其实现高性能的位置伺服控制比较难。目前摆动气缸伺服定位的精度还不能满足实际应用的需求。本文对比例压力阀控制的摆动气缸位置伺服系统线性化数学模型、非线性摩擦力的补偿方法的建立以及对控制策略进行了理论分析和仿真试验,以期获得性能较好的气动位置伺服系统。首先,本文对摆动气缸和比例压力阀进行了特性分析,详细地描述了摆动气缸的外负载和摩擦力的情况,对系统进行详细地分析,建立了较为完整的非线性数学模型并进行了合理的线性化。其次,分析了由非线性摩擦力矩引起的系统稳态误差及粘滑振荡现象;在此基础上提出采用带摩擦力矩补偿的双环控制,其内环为压力控制环,外环为速度控制环,外环采用了摩擦力矩观测补偿器来减小非线性摩擦力矩对系统性能的不良影响。试验结果表明:与仅有速度控制环的控制策略相比该方法提高了系统的稳态精度和动态性能。最后,本文对控制策略进行了详细的研究和设计,通过仿真验证了方案的可行性和有效性。针对系统易受外干扰的特点分别分析并比较了传统PID控制和灰色PID控制,仿真结果表明提出的灰色PID控制方法是稳定和有效的,系统在抗干扰和抗摄动能力方面都有明显的提高。更多还原

【Abstract】 Pneumatic technology, which has a series of obvious advantages, is applied widely in industry production more and more, and becomes a rigueur means of automation. Entering into 1990’s, pneumatic technology is largely beyond the traditional blind area and comes through a quickly develop. As the leading study domain, pneumatic servo technique has a regard for the people. Pneumatic servo positioning technology can realize high accuracy arbitrarily point automatic positioning when cylinder moves in high velocity and break through the traditional pneumatic positioning method. Based on the requirement for engineering upgrading of pneumatic automatic equipment that has advantages such finer feasibility and higher ratio of property and price in middle and small enterprises, this paper introduced a low cost linear cylinder position control system based on a proportional pressure valve. The emulation result indicated that it has a satisfactory control performance, thus, it can be expected to generalize and utilize in variously engineering regions. In the field of industrial automation, there is a lot of requirements for rotation position servo control. Therefore, it has practical value to study on the pneumatic rotation position servo control.Pneumatic rotary actuator is an actuating device of rotate motion used widely in pneumatic system. However, its small stoke and large friction torque make it more difficult to implement angular position servo control of high performance. At present, the positioning precision could not meet the practical requirement. In this paper, a pneumatic rotary actuate position servo system with proportional pressure valves as the control devices is studied. The study is conducted in the following aspects: method of establishing linear model, compensation method of nonlinear friction, control strategy and so on. In order to obtain a better pneumatic servo control system.First of all, this paper has analyzed the characteristic of rotary and flow promotional valve, described the load and friction situation .On the basis of the analysis, this paper has derived the flow-pressure equation and Balanced equation of system, thus set up the non-linear mathematics model, has carried on the rational linearization.The system steady-state error and the stick-slip phenomenon caused by the nonlinear friction are analyzed. A dual-loop control strategy with friction compensation for the system are proposed. The controller has an inner pressure difference control loop and an outer velocity control loop. In the outer loop, a simple friction compensator is used to eliminate the negative effects of the nonlinear friction. Simulation results show that the system performance using the proposed control strategy is better than that using the control strategy with position control loop only. At the end, the pivotal job of this paper is to detailed research and design the control strategy, and to confirm the feasibility and the validity through the simulation. According to the system characteristic which is easily influenced by disturbing effect, my paper has analyzed and compared traditional PID control and grey PID. This method received good result. The simulation results indicated that grey PID is stable and effective. The system has enhanced both the anti jamming and the anti perturbation ability.更多还原